Improvement in ore-roasting furnaces



Y 2 Sheets-Sheet 1. 1 W. E. GIFFORD Ore-Roasting Furnace.

No. 219,634. Patented Sept. 16, I879.

\NIT[\|ESSESZ N. PETER$. PHOTOLITHOGRAPHER. WASHINGTON u c 2 Sheets-Sheet 2.

Patented Sept. 16, 1879.

W. E. GIPPOR-DQ Org-Roasting Furnace;

\N ITNESSESI UNITED STATES PATENT QFFIGEQ WILLIAM E. GIFFORD, orBROOKLYN, ASSIGNOR to HIMSELF AND EDWIN BOLITHO, on NEW YORK, N. Y.

IMPROVEMENT IN ORE-ROASTING FURNACES.

Specification forming part of Letters Patent No. 2 19,634., datedSeptember 16, 1879; application filed August 29,1878.

.To all whom it may concern:

Be it known that I, WILLIAM E. GIFFORD, of Brooklyn, in the county ofKings and State of New York, have invented certain new and usefulImprovements in Furnaces for Roastin g Ores; and I do hereby declarethat the following is a full, clear, and exact description thereof.

My improved furnace may be used for roast ing ores generally, but ismore especially adapted for roasting crushed ore containing pyrites orother sulphides requiring careful and thorough work.

This invention consists in the combination, in a furnace, of a series ofhearths divided into narrow sections, lying one above the other, withsuitable inlet-pipe and connecting arched pipes for supplying air to thehearths; also,

in a furnace constructed in sections and tiers,

and forming the sections and floors of slabs or tiles, spanning withoutarching the distance between the said parallel walls, and arranged oneabove the other to form a series of tiers in each section, the tilefloor being omitted for a suitable distance alternately at front andrear, and the several tiers in. each section communicating by theopenings thus left with each other alternately at opposite ends; also,in a furnace constructed in sections, side by side, and tiers, one abovethe other, and communicating alternately at opposite ends, and providedat the top with a transverse flue connecting the different sections, andallowing the gases therefrom to mingle in and be carried off by thecommon flue; also, and finally, in the combination, with a furnaceconstructed with ore-spaces or tiers one above the'other, andcommunicating with each other alternately at opposite ends, and fluesconnecting it directly with a chimney, the floor of the lowestore-chamber leading from the fireplace, of a heater arranged to beheated by the products of combustion from the fire-place, and connectedbya suitable uptake with the orespaces, all of which will be more fullyhereinafter set forth.

My furnace may be employed for different The accompanying drawings forma part of this specification, and represent what 1 consider a goodmethod of carrying out the invention.

Figure l is a vertical longitudinal section.

Fig. 2 is a front elevation, partly in section;

The sectional portion is in two different planes, the extreme left ofthe figure being on the line 00 0c in Fig. 1, and the middle of thefigure be ing on the line yyin Fig. 1. Fig. 3 is a longitudinal section,showing the doors upon front and rear through which the ore ismanipulated by proper tools, the products of combustion acting directlyupon the ore; Fig. 4, a front elevation of the same, partly in section;and Fig. 5, a detail view. I

Similar letters of reference indicate corresponding parts in both thefigures.

I construct my furnace in sections and tiers, the term section in thisspecification meaning a lateral division of the furnace from the middleof one partition to the middle of the next, and the term tier meaning avertical division from one floor of tiles to the next above. Thesections are of such width that the spaces between the partitions may besimply covered with tiles or slabs of moderate thickness withoutarching. These tiles form, also, the floor of the next tier above. The

width of this space may be eighteen inches,

more or less.

The tiers are of such height as to allow sufficient room for the passageof air through the spaces and for manipulating the ore on the tiles.This height may be such as to leave the spaces from six to nine incheshigh.

The length of the furnace is such as to allow the ore in the spaces tobe manipulated from either end. This length may be fifteen feet, more orless.

The mode of construction is as follows: The proper foundation beingprepared, a series of parallel walls is built (the two outer walls beingof greater thickness) about fifteen feet long and about eighteen inchesapart, and carried to a proper height forthe top of the flue B. A floorof tiles is then laid over the whole, the edges of the tiles meeting onthe middle of each wall. The spaces between the walls thus coveredconstitute the fire-places A, having grates and ash-paus below. Rows offurnace-blocks are then'laid upon the floor of tiles, one row over eachof the walls, and forming an upward continuation of thesame, and thewhole is again covered with tiles. The spaces thus covered form thefirst tier of ore spaces, 0. Furnace-blocks are again laid and coveredwith tiles as before, thus forming the second tier of ore-spaces, D. Thetiers E and F, and more if desired, are formed in a similar manner.

It is preferable to make the spaces in the upper tiers somewhat higherthan those in the lower tier by the use of the higher furnaceblocks ortheir equivalent.

In laying the floors of tiles a certain length of tile is omitted atalternate ends, leaving openings connecting the different tiers, andallowing the upward passage of gases and the downward transfer of ore. Atransverse flue, G, is then constructed, the tiles covering it beingsupported by detached blocks or columns, each resting on the corners offour tiles below and supporting the corners of four tiles above. Thisallows the gases from the different sections to mingle in the commonflue.

In the drawings the flue G extends only about half-way from the front tothe back of the furnace; but when the number of sections is large therequired flue capacity may be obtained by extending the line from thefront to the back of the furnace. The flue G leads to one side of thefurnace and connects with a sulphuricacid chamber, either directly orthrough intervening dust-chambers, arsenicfiues, &c. The joints at thetop of the furnace are covered and made tight by proper means. Thejoints in the interior need not be tight either between the differentsections or between the different tiers. In fact, the whole structuremay be supported by detached blocks or columns instead of continuousrows of blocks; but it is preferable to have the joints closely matchedto secure strength and smoothness of the interior and to facilitate theuse of furnace-tools.

The front and back walls, which are supposed to have been builtsimultaneously with the interior above described, are provided with theapertures S T S S communicating with the orespaces. Each of theseapertures, except S, S and T, allows access of tools to two tiers. Theseapertures are closed by doors, which may be provided wit-h registers toregulate the amount of air admitted, and may also be slotted to allowthem to be nearly closed while the tools are being used. The pipe H,which may be of clay, extending through the flue Gr, represents a modeof introducing ore from any suitable charging arran gement or hopperabove.

The heatersL M N consist of a series of return-bend cast-iron pipes, M,connected with the horizontal pipes L N. The pipe L, Fig. 2, extendsoutside the furnace to receive cold air, and the pipe N terminates inthe uptake 0, through which the heated air reaches the ore-spaces. Anysuitable form of heater may be used.

In the drawings a separate heater is shown for each section but they maybe combined.

The underground transverse flue V receives the gases from the firesafter they have passed the heaters and conducts them to a chimney.

In operating thefurnace, the fires are so managed as to keep the furnaceat a uniform temperature, and as the ore reaches the lower tier, 0,(already at a high temperature. partly owing to the oxidization of thesulphur,) this tier may be maintained at a red heat, even though theheat due to the fuel in the fireplace A has to be conducted throughtiles of moderate thickness. The temperature in the half of the spaces 0nearest the door S Fig. 4, where the ore receives its final heat, may besuch as to decompose the sulphates formed and leave only oxides, or suchas to leave certain sulphates in a condition suitable for lixiviation.

Referring to Fig. 1, S represents the door of the fire-chamber, and Sthe exit for the roasted ore. S S S represent doors governin g passagesupon opposite ends, each of which allows the operator access to twofines or hearths alternately.

The products of combustion from the firebox A pass through the finesBinto the chambers holding the pipes L M N, and escape through a properchimney, V. Air is admitted at N, which, circulating freely through thepipes M and becoming heated, passes from the pipe L into the passage 0,thence to the seyeral alternate hearths, and escapes, as has been shown,through the lateral passage G.

The hearths being all of a heat sufficient for the purpose, the ore isfed throu g ha proper hopper at H, and falls upon the hearth of thechamber F, from whence it is forced by a proper tool inserted throughthe door T a little past midway of that hearth. The operator, throughthe door S then draws it forward until it falls upon the hearth of thechamber E, from whence, through the doors S and 8, it is forced over thehearths of the chambers D and G, and is made to exit through the door SThe modification shown in Figs. 3 and 4 is constructed as beforedescribed, except that no air-superheater is used, however, and theproducts of combustion are allowed to come into direct contact withtheore. The flues B are not connected with the chimney directly, butopen into the spaces 0, and the products of combustion are taken off atthe top after passing over the ore. The ore is introduced into the flueB, and is drawn oft" roasted through the openings I, just within thebridge-wall, into a cross-channel, K, into which all the said openingsempty. The manner of operating is similar to that described withreference to Figs. 1 and 2.

I claim as myimprovements in ore-roasting furnaces or kilns- 1. Incombination with hearths divided into narrow sections, and lying oneabove the other, as shown, the inlet-pipe N, pipe L, leading to theorechambers, and the connecting arched pipes M, for transferring theheat from the products of combustion to the desulphurizing air enteringthe furnace, as herein specified.

2. A furnace constructed in sections and tiers, consisting of front andrear walls, a number of parallel Walls extending from front to rear andforming the sections and floors of slabs or tiles, spanning withoutarching the distance between the said parallel walls, and arranged oneabove the other to form a series of tiers in each section, the tilefloor being omitted for a suitable distance alternately at the front andrear, and the several tiers in each section communicating by theopenings thus left with each other alternately at opposite ends,substantially as described. 7

3. A furnace constructed in sections, side by side, and tiers, one abovethe other, and communicating alternately at opposite ends, and providedat the top with a transverse flue connecting the different sections, andallowing the gases therefrom to mingle in and be carried oft by thecommon flue. substantially 1 described. v

4. The combination, with a furnace constucted in tiers or ore-spaces G DE F, one above the other, and communicating with each other alternatelyat opposite ends of a fireplace and flues, B V, connecting it directlyIn testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

WM. E. GIFFORD.

Witnesses:

W. OoLBoRNE BROOKES, H. A. J OHNSTONE.

